Grate bar assembly for a rock crusher

ABSTRACT

4. A GRATE BAR ASSEMBLY FOR A ROCK CRUSHER COMPRISING: AT LEAST ONE LOWER GRATE ELEMENT HAVING BARS SPACED BY OPENINGS EXTENDING FROM THE UPPER FACE TO THE LOWER FACE THEREOF, AND AT LEAST UPPER GRATE ELEMENT HAVING BARS SPACED BY OPENINGS EXTENDING FROM THE UPPER TO THE LOWER FACE THEREOF, SAID UPPER GRATE ELEMENT BEING SUPPORTED ON SAID LOWER GRATE ELEMENT FOR READY REMOVAL AND REPLACEMENT WHEN WORN, THE OPENINGS IN SAID UPPER GRATE ELEMENT BEING OF A SIZE TO PERMIT PASSAGE THERETHROUGH OF CRUSHED MATERIAL OF A DESIRED DIAMETER, THE OPENINGS IN SAID LOWER GRATE ELEMENT BEING OF SIZE AT LEAST EQUAL TO THE SIZE OF THE OPENINGS IN SAID UPPER GRATE ELEMENT SO AS TO NOT IMPEDE PASSAGE THERETHROUGH OF SUCH MATERIAL PASSED THROUGH THE OPENINGS IN SAID UPPER GRATE ELEMENT, THE OPENINGS IN SAID UPPER AND LOWER GRATE ELEMENTS BEING IN REGISTRY, SAID UPPER GRATE ELEMENT BEING FORMED OF HIGH ABRASION RESISTANT METAL, SAID LOWER GRATE ELEMENT BEING FORMED OF METAL OF HIGH STRENGTH.

March 18, 1975 J. F. aoNARRxGo. JR Re. 28,368

GRATE BAR ASSEMBLY FOR A ROCK CRUSHER Original Filed Oct. 3, 1969 Jasaav/r' 9m/maeva United States Patent Reissued Mar. 18, 1975 Matter enclosedin heavy brackets appears ln the original patent but forms no part ofthis reissue specilication; matter printed in italics indicates theadditions made by reissue.

ABSTRACT OF THE DISCLOSURE A rock or ore crusher is provided with agrate bar assembly through which falls comminuted material as it istriturated by the impact member moving within the crusher. Such gratebar assembly is fabricated of abrasive resistant metal and is relativelyexpensive. The grate assembly of the present invention is constructed ofa lower grate section and an upper grate section which may be replacedwhen worn or abraded without the necessity of replacement of the lowergrate section. Interlocking means secures the sections together.

The present invention provides a new and novel grate assembly for ahammer mill or other rock or ore crusher.

The primary object of the present invention is to reduce the expenseconnected with maintaining a rock or ore crusher grate assembly ineicient operation and condition.

Another object of the present invention is to reduce the material losswhen replacing worn grate bar elements in a hammer mill or othercomminuting apparatus.

A further object of the present invention is to provide, in a rockcrusher, a grate bar assembly having a more or less permanentlyinstalled lower section subject to minimal itl wear and one which may befabricated of less expensive l steel than manganese steel and incombination with a replaceable top section.

A still further object of the present invention is to provide a grateassembly having many interchangeable grate bar elements so as toaccommodate various wear conditions in a rock or ore Crusher apparatus.

These and other objects of the present invention will be apparent fromthe following description when taken in connection with the annexeddrawing in which:

FIG. l is a side elevational view of a hammer mill with portions brokenaway, showing the grate bar assembly of the present invention installedtherein.

FIG. 2 is a side elevational, exploded view of the grate bar assemblyaccording to the present invention, and portions being shown in section,and as seen on line 2-2 of FIG. l.

FIG. 3 is a top view of an end portion of one of the upper grate barelements.

FIG. 4 is ari exploded view in perspective of end portions of the upperand lower grate bar elements of the present invention as seen on line4-4 of FIG. 2 and on a larger scale.

FIG. 5 is a view in perspective of end portions of multiple grate barelements of the present invention with portions broken away, and

FIG. 6 is an exploded end view in section of a one-piece lower grate barelement with a single grate bar upper element at a and a multiple gratebar upper element at b.

With reference to the drawing in detail, in FIG. l the numeral 10designates a hammer mill of conventional construction having a shaft 12carrying a rotor 13 and hammers 14. The numeral designates the improvedgrate bar assembly according to the present invention having lower gratebar elements 22 and upper grate bar elements 24 arranged with the lowerfaces of the elements 24 in superimposed abutting relation with respectto the upper faces of the elements 22.

Openings, indicated generally at 26 in FIG. l` extend through the gratebar assembly 20 and provide passages for the comminuted material astriturated by the action 0f the hammers 14 whirling in close paths withrespect to the upper faces of the upper grate bar elements 2.4A

An important feature of the present invention is that the grate barassembly 20 may be fabricated of a onepiece lower grate element or ofseveral types of lower bar elements 22 and upper bar elements 24, sothat many combinations of bar elements may be made to enable the used ofthe mill to most eciently operate and at the lowest cost of maintenance.

In FIGS. 3 and 4 it will be seen that the lower grate bar element 22 isa single bar having spaced bosses 28 projecting from one side andwhich-with the abutting side of the next adjacent bar elementform theopenings 26.

Similarly, the upper bar element 24', as seen in FIG. 4, is a single barwith bosses 30 also forming the openings 26 when in place in the mill 10with other upper bar elements 24' in side-byside abutting relation.

In FIG. 5 is shown another embodiment of the present invention in whicha lower grate bar element 22", and an upper grate bar element 24", is ofmultiple construction and each having the equivalent of three singlebars having a plurality of openings 26 and having on one side bosses 28and 28" respectively.

In FIG. 6 the grate bar assembly 20 has a one-piece lower bar element22" which accommodates itself for use either with a single bar element24', as at a, or with a multiple bar element 24", as at b.

A further feature of the invention is the provision of interlockingmeans for the upper and lower bar elements, in either the single ormultiple form of each. This comprises, in a preferred embodiment asshown in FIGS. 3 and 4, a tongue 32 depending from the lower face of theupper bar element 24. The tongue 32 tapers inwardly from its upper endto its free end and is provided on each of its four faces with a groove34.

The lower bar element 22 is provided in each of its end portions with anopening or socket, as at 36 in FIGS. 3 and 4, conformably-shaped toreleasably receive the adjacent tongue 32. Each of the sidewalls of thesocket 36 is provided with a longitudinally extending ridge or boss 38which is conformably-shaped to snugly tit into the respective groove 34of the adjacent tongue 32 when the upper and lower bar elements 24 and22' respectively are assembled to form the complete grate bar assembly20, as in FIG. l.

In FIG. 5 the multiple type of lower bar element 22" is shown to have asocket 36' so as to interlock with a similarly formed tongue on amultiple type of upper bar element 24".

A feature of the interlocking tongues and sockets is that they rigidlylock the lower and upper bar elements together when assembled and areeasily separated by the application of a tap with a punch through theopen end of such a socket. it being understood that each socket ex tendsfrom the upper face to the lower face of the lower bar element in eachof its forms. It has further been found that the provision of thegrooves and conformably-shaped bosses add to the rigidity of theassembled grate.

It will be therefore apparent that the provision of mul-` tiple barelements. single bar elements and of the one-piece lower bar element,enable the user of the crushing device to meet all conditions ofrelatively soft or hard rock, ores,

or the like, `ind that when a particular upper bar element or set ofupper bar elements have been worn to the point of being ineticient, eachor all of them are easily and quickly removed and replaced with new topgrate bar elements in any desired combination. While the provision ofthe tongues and socket is believed to enhance the invention, they may beomitted from the end portions of the upper and lower bar elements andthe upper bar elements clamped. bolted, or otherwise secured in the millas is presently practiced with grate bar structures not having the upperand lower elements of the present invention.

The assembly oi upper and lower bar elements to form the grate assemblypermits the use of metals and alloys having relatively great strengthand relatively low resistance to abrasion for the supporting lower barelements. with the upper bar elements fabricated of metals or alloyshaving the greatest resistance to abrasive wear without undue regard toinherent strength.

The objects of the present invention are therefore met and while onlypreferred forms of the invention have been shown and described, it is tobe understood that other embodiments of the invention are contemplatedand may be practiced within the scope and terminology of the appendedclaims.

I claim:

l. ln an apparatus for comminuting rock, ore, or the like. suchapparatus having an open upper end. an open lower end, and an impactingmember =i `posed between said upper end and said lower end and auaptedto comminute material received through said upper end. ing grove, and

a grate device extending inwardly of and adjacent said apparatus lowerend and in the path of movement of material comminuted by said member,said device including at least one lower element having an upper faceand a lower face, and removably secured to said apparatus, at least oneupper element having an upper face and a lower face positioned insuperimposed abutting relation with respect to said lower element, saidupper element and said lower element being provided with cutawayportions extending from the respective upper faces to the respectivelower faces for the passage therethrough of comminuted material,

the cutaway portions of said upper and lower elements being in registry,and

interlocking means carried by said upper and lower elements, said meanscomprising a tongue depending from the lower face of said upper elementreleasably received in an opening extending from the upper face of saidlower element to the lower face of said lower element.

2. The apparatus according to claim 1, in which said tongue is providedwith at least one longitudinally extending groove, and

a longitudinally extending boss in the adjacent wall of said opening,

said boss being conformably shaped to said groove.

3. The apparatus according to claim 1, in which said tongue tapersinwardly from the upper end to the lower end thereof.

4. A grate bar assembly for a rock Crusher comprising: at least onetower grate element having bars spaced by openings extending from theupper tace to the lower face thereof, and at least one upper grateelement having bars spaced by openings extending from the upper to thelower face thereof, said upper grate element being supported on saidlower grate element for ready removal and replacement when worn, theopenings in said upper grate element being of a size to permit passagetherethrough of crushed material of a desired diameter, the openings insaid lower grate element being of size at least equal to the size of theopenings in said upper grate element so as to not impede passagetherethrough of such material passed through the openings itz said uppergrate element, the openings in said upper and lower grate elements beingin registry, suid upper grate element being formed of high ubru4 sionresistant metal, said lower grate element being formed of metal of highstrength 5. A rock or ore Crusher comprising a shaft fournnled within ahousing for rotation, a rotor carried by said shaft. hammers carried bysaid rotor, a grate bar assembly within said housing adjacent to andspaced from said rotor and adapted to coact with said hammers to crushand reduce in size material when placed in said housing, said assemblyincluding an upper grate element formed of high abrasion resistantmetal, a lower grate element formed of a metal of high strengthsupporting said upper grate element for ready removal of said uppergrate element for replacement when worn, each of said upper and lowergrate elements having bars spaced by openings etc tending from the upperfaces to the lower faces thereof, the openings of said upper grateelement being of a size to permit passage therethrough of crushedmaterial of a desired diameter,

the openings of said lower grate element being of a size at least equalto the size of the openings of said upper grate element s0 as not toimpede passage therethrough of such material passed through the openingsin said upper grate element, the openings in said upper and lower grateelements being in registry` References Cited The following references,cited by the Examiner, are of record in the patented file of this patentor the original patent'.

DONALD G. KELLY, Primary Examiner U.S. Cl. XR. 24l-89.2, 294

